Aerial navigation instrument



1930. G. ESTOPPEY 1,784,929

AERIAL NAVIGATION INSTRUMENT Filed April 10, 192 2 Sheets-Sheet l 2+ T I /4 7 3 a L 1 M m mm: mi

5 i v m" M. Z I i II" 1 /7 i 9 0 4' l a vI I LI l 1 a L 1 4 7 .E 30k 3a W o u 25 INVENTOR /5 615026155 [STOPPEY ATT Dec. 16, 1930. G. ESTOPPEY AERIAL NAVIGATION INSTRUMENT Filed April 10, 1926 2 Sheets-Sheet 2 INVENTOR foeeas 5.5 op/ 5 Y BY ATTOK Patented Dec. 16, 1930 UNITED STATES PATENT OFFICE GEORGES ESTOPPEY, OF DAYTON, OHIO AERIAL NAVIGATION INSTRUMENT Application filed April 10, 1926. sin-m1 m5.'1o1,121.

This invention relates to an apparatus to as the description of my invention proceeds; be used on aircraft for determining the reference, for a full understanding, is had to ground speed, air speed, wind speed and other the accompanying drawings in which: factors necessary to successfully navigate the Fig. 1 is a central section through the inaircraft and for determining the factors restrument.

quired for bombing purposes. Fig. 21s a planview thereof.

The main object of this invention is to pro- Fig. 3 1s a partlal View showing the bottom vide an apparatus in which the vectors repreof the telescope. senting the ground, air, and wind speeds are F1g. 4 is a part sectional view of the eye 30 resolved into a mechanical triangle. plece and of the telescope, and

A. further object of the invention resides in Flg- 5 is a schematic drawing showing the the manner in which this triangle is formed mechanism of the instrument. and the mechanical features to effect the same. The device consists in the main of a. hous- Particular emphasis is to be placed on the ing 1, and a telescope 2. The housing con- 15 means embodied herein for determining the tains a compass 3 slidably mounted in the o5 angle the ground course makes with the true forward end thereof on a micrometric screw north, the true direction of the wind and other 4 to be described later. F ixedly'inounted in factors governing flying and bombing'calcuthe rear thereof is a watch or timing element lations which depend on angular measure- 5 for the purpose of rotating an altitude in- 20 lnents, dicator 6 at a predetermined speed. This in- Briefly stated. the above objects are accomdicator is adjustable with reference to a dial plished by providing three calibrated arms in 7 for altitude calibrated in some convenient pivotal relation to one another. The air speed unit. The compass, heretofore mentioned,

is determined from an extraneous means and possesses a graduated disc 8, the index numthe value found set on the air speed arm. The ber of which is directed toward the magnetic instrument is then aligned with the ground pole. Aring9pivotally mounted on the comcourse which operation automatically deterpass'moves around the compass cover and has mines the airspeed vector. The ground speed scribed thereon an index 10. The compass is is then determined and in making this deteroperated by the micrometric screw 4, engagminatiou the ground speed vector is automatiing a nut 11. Comprising a part of the housso callv set. This operation further causes the ing 1 are two bars movable with reference to wind speed vector to assume its position. one another; namely, an airspeed bar 12 and During this operation a magnetic compass is a wind speed bar 13. The airspeed bar 12 is moved to the apex of the triangle from which rigidly fixed to the aircraft and parallel to the relation of the various vectors with the the axis thereof, by a support 14 which is true north can be determined. fixed to a stud 15 which in turn is fixed to a It is thus seen that an instrument, such as support 19 by which the whole apparatus is this invention provides, eliminates the manattached to the aircraft. Astop screw 17 and ual setting of the various vectors, is certain slot 18 are provided for assembly purposes of operation. and very efficient, in that the and for drift angle determination. The wind vectors assume their respective positions sispeed bar 13 slides in the sliding member 20 multaneously. i am aware that there are which pivots about the stud 21 fixed to the other devices for accomplishing the same obsliding member 22 which slides along the airjcct, in part. as this invention, such as the despeed bar 12. The other end of the wind vice disclosed by the U. S. patent to Pollen speed bar pivots about the stud 23 fixed to the et a1. 1314.428, but that device is objectioncompass 3. The wind speed bar has avernier able due to the necessity for manual operation. or index 24 fixed at one end of the sliding and its resulting slowness of operation. member 20, and the air speed bar has an inith the above objects and advantages in dex 25 fixed to one end of the sliding memview and which will be more fully setforth ber 22. An index 26 fixed to the bar 12 and 1 pivoting about axis 27 indicates the drift angle on a dial 28 fixed to the housing 1. The watch or timing element 5, as was before mentioned, is fixed in the housing 1 and is wound through bevel gears 29 and 30 connected to bevel gears 31 and 32 which are operated by the use of a hand wheel 33, the use of which will be described later on. On the same shaft with the gears 30 and 31, and operated at the same time, is the gear 34 which meshes with another gear 35'as in Fig. 2 fixed to and rotatin the micrometric screw 4. A ground speed ar 36 is mounted parallel to the axis of the micrometrio screw 4 and at the one side of the housing 1 and is rotatable with the housing about the stud 15 as an axis. An index 36 mounted on the one side of a sliding member 37 integral with the compass indicates ground speed on the scale on the ground speed bar 36.

The ground speed is determined by observing an object on the ground thru the telescope 2, which consists of a telescope housing fixedly mounted in the rearmost portion of the housing 1 and adjacent the watch 5. An

opening 38 cut in the side of the telescope permits the indicator 6 of the watch to pass in the sighting field of the telescope. A series of lenses 39, 40, 41 and 42 are mounted at intervals in the telescope, which are focused upon a movable reticle which indicates upon a fixed prism 43 operating in conjunction with a movable prism 44, by which means an object can be sighted on the ground. The reticle 45 is mounted on a stabilizer 46 dampened by dashpots 47.

The movable prism 44 is moved by a driving mechanism consisting of a vertical micrometric screw 48 and a nut 49, said nut-having a stud 50 mounted therein. This stud operates in a guideway 51 at the one end of a lever 52; the other'end of said lever beingattached to the movable prism. The vertical micrometric screw is integral with a vertical shaft 53, said shaft having mounted at the top end thereof a bevel gear 54 meshing with another bevel gear 55 which is attached to the hand wheel 33. In this manner both the horizontal micrometric screw 4 and the vertical screw 48 can be operated at the same time by the hand wheel. p

By the mechanism described it is possible to resolve the vectors of the ground speed, air speed, and wind speed into a mechanical triangle which is accomplished in the following manner:

The apparatus is set for the operation bylacing the pivot of the compass 3 directly eneath the pivot of the drift angle scale 28 on the axis as the stud 15. The air and wind speed bars are superposed on one another when the compass is in this position and par-;

ground speed arm. Any oballel with the ject is then sighted thru the telescope, and the housing 1 being moved.

moved by a handle 57 until they object is moving parallel with the axis of; the instrument, i. e., parallel with the ground s eed arm. Since the air speed bar is rigi ly fixed to the aircraft and in a line parallel to the axis thereof it will be seen that the air and wind speed arms will remain in their superimposed osition relative to one another during tii about points 15, 27 and 23 as an axis. -The drift angle at this time may be read from the quantity of the air speed vector is attained.

is operation and will pivot being determined by extraneous Thus the I The needle 6 of the clock 5 is then set on the dial to correspond with the altitude of the airplane by turning the knob 56 mounted on top of the watch. which regulates the position of the movable prism 44 is at position FA shown-in'dotted lines on the micrometric screw, as will be seen by observing Fig. 5. Sighting line L-L at this time makes an angle a with the vertical and the vertical axis of the compass 3 and corresponds with the axis of the stud 15'. The nut 11 of the micrometric screw 4 is also coincident therewith. It is not necessary to follow the steps in the order as given, it being sufficient if the instrument is set as is now set At this time, thefnut 49 I forth which is in condition to determine the ground speed vector.

To do this an object is picked up thru the telescope which is passing along the ground course. When said object passes in the sight line L-L, the hand wheel 33 is turned and the watch started simultaneously. The telescope is synchronized with theobject on the ground by turning the wheel 33 this way until the pointer 6 of the watch passes in the sighting field of the telescope, when the cranking of continued.

As the wheel 33 is being turned the nut 11 isbeing moved forward by means of mechans ical connections as described, andwith-said; v

at the required speed andcontinued inthe movement of y the wheel 33.is dis nut the compass andgroundspeed index-are discontinued the ground speed maybe read fromthe setting of the index onthe ground After the cranking has been speedscale and ground direction by refer ence to the compass.

By this operation, the last vector,-' jthe wind wind speed baris' causedspec is found. As the compass 3'and nut 11 are belng moved the to assume the position shown in- Fig;,,5. As

the compass 3 has been dis the wind speed bar has been displaced, as itis fromt origlnal- POSltlOII to position K,i,so,-alsoj has pivotally mounted at its one end to the compass and slidably mounted on the air speed bar. The direction and quantity of this wind speed vector is now determined merely by noting the angle which it makes with the ground s eed bar or by reference to the compass and by reading the setting of the index.

By merely examining the various indicating means of the instrument, the ground speed can be read, the drift angle, the air speed and the wind speed and due to the fact that the compass has been moved forward with the ground speed index, a comparison of the vector arms 'with the magnetic needle indicates the true direction of the wind with reference to magnetic direction, the true course of the aircraft, i. e., the ground course and the drift angle in terms of north and south.

Having thus fully described my invention what I claim as new and desire to protect by Letters Patent of the United States is:

1. An instrument for determining automatically the relation between the ground speed, air speed and wind speed vectors for a moving craft comprising means for resolving the vectors of the various speeds into a mechanical triangle, said means comprising a vector arm for the air speed, a support for permanently fixing said arm to the air craft, parallel to the fore and aft axis thereof there being an air speed scale thereon and frictionally slidable index therefor, a vector arm for the ground speed, said arm bing movable about the air speed arm support as an axis, there being a scale thereon and a slidable index therefor, a vector arm for the wind speed, a scale and slidable index therefor, said wind speed index being pivotally attached to the air speed index, said wind speed arm being pivotally mounted on the ground speed index, means for aligning the ground a speed vector with the ground course and rotatable means for determining the ground speed, said means synchronously actuating the ground speed index.

2111 an instrument of the class described for aircraft, the combination of a supporting member fixed t0 the aircraft, an air speed arm fixed to said support, parallel to the fore and aft axis of the aircraft and having graduations thereon for indicating air speed, a slidable index thereon, a wind speed arm having graduations thereon for indicating wind speed, a slidable index therefor, said index being pivotally mounted on the air speed index, a ground speed arm pivotally mounted on the air speed support as an axis a slidable index therefor on which said win speed arm is pivotally mounted, and means for determining the ground speed, said means actuating the ground speed index which in turn causes the various arms to assume a triangle proportional in value and direction to the speed which they represent respectively.

3. The combination as set forth in claim 2 characterized by 'havin a graduated scale supported by the groun speed support and movable with the ground speed arm when the ground course is determined for indicatmg the drift angle.

4. The combination as set forth in claim 2, a magnetic compass carried by said ground speed index.

'5. In an instrument for aircrafts, the combination of a support, an air speed scale attached to the support parallel with the fore and aft axis of the aircraft, a housing revolvable about said support, a ground speed scale carried by said housing, a'wind speed scale a slidable index for each scale, said ground speed index being at zero when it is coincident with the axis of revolution of the housing and carried by a micrometric screw extending longitudinally of said ound speed scale, said wind speed scale being pivotally mounted at one end, on the ground speed index and pivotally and slidabl carried by the air speed scale, a telescope or aligning the axis of said instrument with the ground course, means operable in the telescope for determining the ground speed, comprising a micrometer screw, means connecting said screw with the ground speed micrometer screw whereby said ground speed index is moved synchronously with said first-mentioned micrometer screw.

An instrument for determining automatically the relation between the ground speed, air speed and wind speed vectors for a moving'craft comprising means for resolving the vectors of the various speeds into a mechanical triangle, said means comprisin a vector arm for the air speed, a support or permanently fixing said arm to the aircraft parallel to the fore and aft axis thereof, there being an air speed scale thereon and an index slidable therealong, a vector arm for the ground speed, said arm being movable about the air speed arm support as an axis, there being a scale thereon, a magnetic compass slidable along said ground speed arm and providing a slidable index for giving indications of ground speed on saidground speed scale, a vector arm for the wind speed, a scale and a slidable index therefor, said wind speed index being pivotally attached to the air speed index, said wind speed arm being pivotally mounted on the ground speed index, means for aligning the ground speed vector with the ground course and rotatable means for determining ground speed, said means synchronously actuating the ground speed index along its arm.

7. An instrument for mechanically simulating the air-ground-wind-speed triangle of an aircraft and for indicating the true relation of the aircraft with the magnetic north comprising interconnected arms of variable effective length for representing the various 4- nasaeae component velocities, means for determining the round speeds, means interconnecting said first-named means and the ground speed arm whereby the side of the triangle repre- 5 senting such speed is automatically set up as the ground speed is determined and a compass at the apex of said ground speed and wind speed arms. 8. An instrument for mechanically simulating the air-ground-wind-speed triangle of an aircraft and for indicating the true relation of the aircraft with the magnetic north comprising interconnected arms of variable effective length for representing the various component velocities, means for determining the round speeds, means interconnecting said first-named means and the ground speed arm whereby the side of the triangle representing such speed is automatically set up as the ground speed is determined and a magnetic compass actuated simultaneously by said ground speed determining means to assume a position at the apex of said triangle.

9. An instrument for mechanically simulating the air-ground-wind-speed triangle of an aircraft comprising interconnected arms of variable effective length for representing the various component velocities, means for determining the round speed, and means interconnecting said first-named means and the ground speed arm whereby the side of the triangle representing such speed is automatically set up as the ground speed is determined. as 10. An instrument for determining automatically the relation between the various speed vectors for a moving craft comprising means for resolving the vectors of the various speeds into a mechanical triangle, said means comprising vector arm's graduated and pivotally associated and including a groundspeed arm, means for determining the ground speed, and means comprising an index for indicating the ground-speed on said groundspeed arm and for interconnecting said arm and the wind speed arm whereby the length of the side of the triangle representing the ground-speed is automatically set up as the ground-speed is determined. 59 In testimony whereof I afiix my signature.

GEORGES ESTOPPEY. 

